1. Field of the Invention
This invention relates to the transmission of data over communication links and, in particular, to the transmission of full duplex, full motion, live video over existing telephone lines.
2. Description of the Related Art
The use of the telephone system to transmit video as well as voice communications is well known, and has been practiced for several decades. However, existing systems typically are either very expensive, or only allow transmission of images, particularly those which include movement, with noticeable delays, poor transmission quality, or some combination of these problems. In a basic sense, full motion video and in particular full motion interactive video, requires the delivery of a very significant amount of data in a relatively uninterrupted stream. The ability to accomplish this over standard twisted pair copper wire has heretofore not been achieved.
One of the more recent developments in seeking to provide improved video transmission has been the use of dedicated Integrated Services Digital Network (ISDN) lines for the data transmission. Although this has resulted in much improved transmission quality, the expense of ISDN lines still remains a formidable obstacle to their wide use. The use of ISDN systems for video transmission has been disclosed in eg., Dagdeviren et al., U.S. Pat. No. 5,371,534, Aramaki et al., U.S. Pat. No. 5,751,339, and Sahni, U.S. Pat. No. 5,184,345.
An alternative to the transmission of video data over telephone lines is the use of the Internet or other computer networks. The Internet or other computer networks do not have the cost disadvantage of using ISDN lines. However, the Internet relies on grouping the data to be transmitted over it into small component packages of data called packets. These packets are, in general, of unequal length and contain information to indicate where they begin and end, as well as source and destination information. Packets from diverse sources travel over the Internet together and, thus, must be recognized at any intermediate switching point and at their final destination points for recombination with other properly associated packets if successful transmission is to occur. The packeting methodology by its very nature leads to potential delays in transmission and processing, and a degradation in the quality of the transmission. In addition, the ever growing number of users on the Internet has compounded the delay in transmission. Delays and degradation in quality, although generally not critical in voice communications, cannot be tolerated in applications requiring a high data transmission rate such as full-motion, live, full duplex video transmission, particularly if broadcast quality or near broadcast quality video is required. However, to achieve full motion quality audio visual transmission, and to do so in a relatively inexpensive manner, presents a number of significant challenges. Many of these challenges would be overcome if a suitable method, apparatus and system were developed which could take maximum advantage of the existing vast network of twisted pair copper wire which carries the majority of voice telephonic communication today.
The present invention presents a solution to the heretofore unsolved problem of delivering full-motion, live, full duplex transmission of broadcast or near broadcast quality video over existing telephone networks. The benefits from the wide implementation of this technology are almost too innumerable to recount. Among its benefits are the vast expansion of both commercial and recreational use of the video telephone and the creation of a new era of interactive television and telephonic video communications. The potential uses span almost all fields of endeavor, including, for example, the entertainment industry, the financial services industry, the field of corporate communications, hotel and travel services, governmental agency and public services applications, medical services, educational services, and an almost endless variety of consumer applications.
In the field of entertainment for example, television viewers could participate visually and interactively with not only the host of a program, but other viewers as well. Entirely new television broadcast programming formats will become possible. Television news programs could create video chat rooms and solicit immediate viewer reaction to news as it occurs. News organizations could link their vast network of affiliates together to cover news as it happens using their combined resources. Programs directly marketing products or services would be enhanced by the ability of viewers to interact by video as well as by voice with the marketer and other customers.
Inexpensive video conferencing, particularly given the secure nature of hard-wired land line telephonic communications, is more compatible with the needs of many industries, such as the financial services industry, which in the past has had justifiable concerns about transmitting information over the Internet. Moreover, the present practice of business and financial community conference call reporting to the investment community can be greatly enhanced by providing video as well as audio interactivity among participants. In the hotel and travel industry, the availability of video transmission and reception at hotels enhances the services available to a business traveler who is enabled to maintain constant interactive point-to-point contact with home, office, and other business associates.
In general, private industry will, if it chooses, have the ready availability to create relatively inexpensively its own closed circuit television network, without the attendant costs of ISDN and T1 lines. Interactive communication between government agencies also has obvious significant advantages, particularly in emergency situations, and the advantages in the medical field of ready accessible visual communication and interactivity for patient diagnosis, monitoring, and the proliferation of services and knowledge between care givers, patients and hospitals is also self-evident. As well, the advantages in the field of education are significant, ranging from video tutoring and "wide area" classrooms to budget reduction as information is offered from a central location with the students enabled to maintain a personal, visual interaction with the instructor.
However, the most obvious beneficiaries of the present invention are individuals who, with the availability of a means to capture video, can, through the use of the present invention, employ standard telephone lines to communicate with another person or a group of others, in broadcast or near broadcast quality video.
The foregoing examples are in no way intended to be exhaustive and many other benefits stemming from the present invention will be obvious to those of ordinary skill in the art.